Necessary preferences
The calculators store unit preference (km or miles), last 5K, 10K, half-marathon, and marathon target times, age, comparison category, optional heart-rate numbers, the last race on the running performance calculator, and your cookie-banner choice in localStorage on this device. These preferences are necessary for the site to remember units, race targets, and shared performance inputs. They are not used to identify you across other websites.
Contact form
On the contact page we load a form from Fillout so you can send a message without opening an email app. Fillout may set cookies on its own domain inside that form. Those cookies are not Google Analytics cookies and are not controlled by the accept or reject choice below. If you prefer not to use Fillout, email yanchi@yanchi.space instead.
Optional analytics
If you accept, we load Google Analytics 4 to measure page views and which calculators people open. Events do not include your race times, heart rate, age, or other inputs. Google may set cookies such as _ga and _ga_*. These are optional. Advertising cookies are not used.
Your choices
Accept or reject optional analytics here, or from the banner on first visit. Reject still keeps necessary preferences working. If you reject after a previous accept, Google Analytics stops and its cookies for this site are deleted. You can also clear this site’s data in your browser.